A110286 a(n) = 15*2^n.

15, 30, 60, 120, 240, 480, 960, 1920, 3840, 7680, 15360, 30720, 61440, 122880, 245760, 491520, 983040, 1966080, 3932160, 7864320, 15728640, 31457280, 62914560, 125829120, 251658240, 503316480, 1006632960, 2013265920, 4026531840, 8053063680, 16106127360

Offset: 0

Author

Alexandre Wajnberg, Sep 07 2005

Keywords

• easy
• nonn

Comments

The first differences are the sequence itself. Doubling the terms gives the same sequence (beginning one step further).

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..235
• Tanya Khovanova, Recursive Sequences
• Index entries for linear recurrences with constant coefficients, signature (2).

Crossrefs

Cf. A007283, A020714, A005009, A005010, A005015, A005029.

Cf. A000079, A051916, A173787.

Programs

Magma

[15*2^n: n in [0..40]]; // Vincenzo Librandi, Apr 28 2011

Mathematica

15*2^Range[0, 60] (* Vladimir Joseph Stephan Orlovsky, Jun 09 2011 *)
NestList[2#&,15,30] (* Harvey P. Dale, Oct 19 2014 *)

PARI

a(n)=15<Charles R Greathouse IV, Oct 07 2015

Formula

G.f.: 15/(1-2x). - Philippe Deléham, Nov 23 2008

a(n) = A000079(n)*15 = A007283(n)*5 = A020714(n)*3. - Omar E. Pol, Dec 17 2008

a(n) = A173787(n+4,n). - Reinhard Zumkeller, Feb 28 2010

Subsequence of A051916. - Reinhard Zumkeller, Mar 20 2010

a(n) = 2*a(n-1) (with a(0)=15). - Vincenzo Librandi, Dec 26 2010

E.g.f.: 15*exp(2*x). - Stefano Spezia, May 15 2021

Extensions

Edited by Omar E. Pol, Dec 16 2008